Differences with postcss-cssnext?
Is there any (beside the fact that this plugin do not disable some features when the browsers scope don't need some) ?
Yea, this project was made from my confusion of your cssnext project, like which one do I use? Seems like I could use that instead, but I'm not looking for fallbacks, so I am just using the plugins that are necessary for me.
That's why this project have a "browsers" option: to disable the thing you don't need (like autoprefixer does).
Does that prevent it from being installed or exclude from processors? If it does then it should speed up the compile time. I might check it out, thanks for pointing that out!
For now it just avoid to run the plugins, but that might be an enhancement to not even download them (=> only npm install packages that are required by the user scope)
Can you explicitly turn off all fallbacks? Maybe we could work together on these enhancements for cssnext?
Yes via the "features" option http://cssnext.io/usage/#features The only two options that will be kept after official migration to postcss-cssnext will be "browsers" and "features" :)